The Role Of As₂O₃Nanopaticles On Leukemia Cells And Effection Of Penetrability Across Blood Brain Barrier

We Prepared arsenic trioxide （As₂O₃） nanopaticles with sol-gel method and characterizedthem with trans-mission electron microscope, scanning electron microscope, energydispersive spectrometer and statistical analysis software of nano-size distribution, anddetermined the concentration of As in the As₂O₃nanoparticles solution with hydridegeneration-atomic fluorescence spectrum method. In vitro test, we studied the role ofproliferative inhibition between As₂O₃nanoparticles and traditional As₂O₃solution （arsenictrioxide） on K562, U937and HL60cells by MTT, we also observed the effection of Asconcentration inside K562, U937and HL60cells with hydride generation-atomicfluorescence spectrum method after using As₂O₃nanoparticles and arsenic trioxide. Then wecompared the inducible effect of apoptosis of As₂O₃nanoparticles and arsenic trioxide onK562, U937and HL60cells by flow cytometry. In vivo tests, animal experiment preliminarydiscussed the permeability across blood brain barrier （BBB）. We infused differentconcentrations of As₂O₃nanoparticles and arsenic trioxide into mouse stomach at one time,then the mice were sacrificed at different time and mouse brains were isolated anddetermined the concentrations of As with hydride generation-atomic fluorescence spectrummethod.The prepared As₂O₃nanopaticles were approximately spherical or ellipse and welldispersive, its diameter were about40nm, and EDS results identified that thenanopaticles were As₂O₃.The inhibition effect of cell proliferation experiments showedAs₂O₃nanopaticles and arsenic trioxide both were able to inhibit the growth of K562, U937and HL60cells. The inhibition rate increased dependent on concentrations and time. And thegrowth inhibition rate of cells treated by As₂O₃nanopaticles was significantly higher thanthat of arsenic trioxide at the same concentration and incubation time. K562, U937andHL60cells were treated with As₂O₃nanopaticles and arsenic acids for three hours, and theAs concentration inside cells increased with drug administration. And at the sameconcentration, the As concentration inside cells treated with As₂O₃nanopaticles higher thanarsenic trioxide. The cell apoptosis experimental result similar with MTT, to a certain extent,As₂O₃nanopaticles and arsenic trioxide were able to induce K562, U937and HL60cellsapoptosis. And the apoptosis rate increased dependent on concentration and time. The growth inhibition rate of cells treated by As₂O₃nanopaticles was significantly higher thanthat of arsenic trioxide at the same concentration and incubation time. The animal testshowed that the As concentration in the brain tissue of mice increased with drugconcentration. And the As concentration in the brain tissue treated by As₂O₃nanoparticleswas obviously higher than arsenic trioxide at the same concentration and time. Drugconcentration were0.5mg/kg and1.0mg/kg, after two hour the As concentration in mousebrain tissue in both As₂O₃nanoparticles and arsenic trioxide could reach a plateau. But thedrug concentration was2.0mg/kg, the As concentration in mouse brain tissue in two groupshad a spike after four hours. And the As₂O₃nanoparticles group was dramatically higherthan arsenic trioxide. When the drug concentration is0.5mg/kg, As₂O₃nanoparticles groupAs concentration in brain tissue was obviously higher than arsenic trioxide, even higher thanthe peak of arsenic trioxide group. When the drug concentration was1.0mg/kg and2.0mg/kg, the As concentration treated with As₂O₃nanoparticles was strikingly higher thanarsenic trioxide after twenty four hours.According to the experimental results we get the following conclusions:（1） We succeed in preparing As₂O₃nanopaticles which diameter is about40nm and hasgood dispersion.（2） As₂O₃nanoparticles and arsenic trioxide both can inhibit proliferation of K562,U937and HL60cells, and the effects are in time and concentration dependent manners. Theinhibition effect of As₂O₃nanoparticles is obviously stronger than that of arsenic trioxide.（3） The intaken ability of As₂O₃nanoparticles and arsenic trioxide by K562, U937andHL60cells in a dose-effect manner. The intaken rate of As₂O₃nanoparticles is higher thanarsenic trioxide. This may be one of the reasons that As₂O₃nanoparticles have a strongerinhibiting effect on cell proliferation than arsenic trioxide.（4） Both As₂O₃nanoparticles and arsenic trioxide can induce the apoptosis of K562,U937and HL60cells in time and concentration manners, and the effect of As₂O₃nanoparticles is significantly stronger than arsenic trioxide.（5） Compared with arsenic trioxide, the permeability of As₂O₃nanoparticles acrossBBB is significantly enhanced and the action time of drug in brain tissue was prolonged.